Hope . — The ‘ S add' of the Upper Nile . 51 1 
required, such as for floats for fishing nets. To construct 
some of these articles the soft corky stem is cut into thin 
slices and pasted together. It is sold in the bazars of Calcutta, 
being brought from the neighbouring marshy places, where it 
grows to a great size. 
Aeschynomene aspera (‘Sola’) itself seems to be a Nile 
plant, for in the Botanical Appendix to Speke’s book is an 
entry — Aeschynomene indica , L., 6 Solah ’ of India, in marshes 
generally 5 0 S. to 2° N. lat. But this range is all south of the 
‘ Sadd ’ region. In September, it is said (the height of the 
dry season), at 3 0 S. lat., this plant lies dead on the dry mud ; 
it grows erect 7 feet high, and is used for floats for nets. 
Ae. Schimperi , Hochst., is another equatorial African plant, 
and is said to be a species of Indian Solah (pith), a bushy 
tree, growing 20 feet high. 
Azolla nilotica is represented in Bengal by A.pimiata y R. Br., 
and the Nile Ottellia by O. alismoides : ¥zYs. — if indeed the plants 
are specifically different. 
Plants which are identical on the Nile and in the Bengal 
swampsare Vossia procera , Trapa natans , Linn .^Pistia stratiotes , 
L., Aldrovanda vesicularis (very rare, though perhaps plenti- 
ful in places), Nymphaea Lotus and N. stellar is , and Cerato- 
pteris thalictroides . Mr. Clarke is inclined to consider Pistia 
stratiotes as the chief constituent of the rotting vegetation in 
the Bengal swamps and jheels , which in the middle of the rains 
forms a floating mass from 6 to 24 inches thick, on which birds 
run and which will often carry a man. And he says that most 
of the plants which float, or grow on floating masses of Pistia , 
other weeds and earth mixed, can also grow on mud ; while 
the whole of the rice-field weeds may grow on such floating 
masses. Even seedlings of trees, as of Bombax and Erythrina , 
sometimes appear plentifully on the floating mass. 
It is by notes such as these which Schweinfurth, Kotschy 
and Peyritch, Mr. Clarke, and other botanists who have been 
great travellers, give us of the habits and habitats of plants, 
that the dry bones of systematic botany are made to live and 
be interesting to the general reader. 
